'I'm bummed to see you go, but I'm also excited to see what you do next,' said the actor.

The cast is also facing an offscreen challenge as they enter the first season without fan favorite Pauley Perrette. "When Michael Weatherly left two years ago, it was a period of adjustment," Cardea says. "I think we’ll probably go through the same thing."

After three guest spots last spring, Diona Reasonover’s quirky Kasie steps into the lab full time. "She’s still a temporary employee," Cardea says. "Around Episode 4 or 5, she becomes permanent."

Rocky Carroll in NCIS.

Another highlight for late fall: an episode shot at Naval Air Station Point Mugu in California. "We’ve got big airplanes and big scope," Cardea says. Speaking of big, Gibbs takes a trip to the Big Easy — as in NCIS: New Orleans— for its season premiere. Best Tuesday since Mardi Gras!